1. Field the Invention
This invention relates to polymers capable of oxidative crosslinking, to a process for their production by reacting copolymers containing carboxylic anhydride groups with hydroxyalkyl amides of unsaturated carboxylic acids to form imides and to the use of the polymers as binders for coating and sealing compositions.
2. Description of the Prior Art
Oxidatively drying binders based on copolymers are known. They are obtained, for example, by esterification of OH-functional copolymers with drying fatty acids (DE-OS 2,728,568) or by reaction of glycidyl copolymers with drying fatty acids (GB-PS 793,776 and 1,227,398).
Due to their price and certain disadvantages in terms of paint technology, including for example slow drying and overcoating problems attributable to a tendency to pull up the overpainted film, these binders have never been successfully adopted for use in practice.
An object of the present invention is to provide new polymers which are capable of oxidative crosslinking, which may be readily be produced from inexpensive raw materials and which satisfy practical requirements in regard to their performance properties.
This object has been achieved by the polymers according to the invention which are described in detail hereinafter. The polymers according to the invention are derivatives of copolymers containing intramolecular carboxylic anhydride groups. They are produced by reacting these copolymers with reaction products, i.e., primarily hydroxyalkyl amides formed from aminoalcohols and olefinically unsaturated monocarboxylic acids, to form imides.